OnDoc/WinSign/Sign.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Text;
using System.Windows.Forms;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Reflection;

namespace WinSign
{
    public partial class Sign : UserControl
    {
        private bool _shouldSign = false;
        private BackgroundWorker _bgWorker = new BackgroundWorker();
        string _signPointsX = "";
        string _signPointsY = "";

        public Sign()
        {
            InitializeComponent();

            this.BorderStyle = BorderStyle.FixedSingle;
            _bgWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(_bgWorker_RunWorkerCompleted);
            _bgWorker.DoWork += new DoWorkEventHandler(_bgWorker_DoWork);
            this.DoubleBuffered = true;
        }

        #region " Properties "

        /// <summary>
        /// The format to save the signature file
        /// </summary>
        private ImageFormat _signatureFileFormat = ImageFormat.Bmp;
        public ImageFormat FileFormat
        {
            get { return _signatureFileFormat; }
            set { _signatureFileFormat = value; }
        }

        /// <summary>
        /// The format to save the signature file
        /// </summary>
        private Bitmap _signatureBitmap = null;
        public Bitmap SignatureBitmap
        {
            get { return _signatureBitmap; }
        }

        /// <summary>
        /// Color of the signature Default BLUE
        /// </summary>
        private Color _penColor = Color.Blue;
        public Color PenColor
        {
            get { return _penColor; }
            set { _penColor = value; }
        }

        /// <summary>
        /// Width of the Signature Default 4
        /// </summary>
        private int _penWidth = 4;
        public int PenWidth
        {
            get { return _penWidth; }
            set { _penWidth = value; }
        }

        /// <summary>
        /// Required points for valid sign
        /// </summary>
        private int _requiredPoints = 20;
        public int RequiredPoints
        {
            get { return _requiredPoints; }
            set { _requiredPoints = value; }
        }

        /// <summary>
        /// Background Image (Bitmap) for sign
        /// </summary>
        private Bitmap _backgroundImageBitmap = null;
        public Bitmap BackgroundImageBitmap
        {
            get { return _backgroundImageBitmap; }
            set { _backgroundImageBitmap = value; }
        }

        /// <summary>
        /// Informs if the sign was present
        /// </summary>
        /// <returns></returns>
        public bool IsValid
        {
            get
            {
                return (_signPointsX.Replace("|","").Trim().Length >= _requiredPoints);
            }
        }
        
        #endregion

        void _bgWorker_DoWork(object sender, DoWorkEventArgs e)
        {
            e.Result = GetSignImage();
        }

        void _bgWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            this.BackgroundImage = (e.Result as Bitmap);
            this.Refresh();
        }

        private void AddtoX(string x)
        {
            _signPointsX = _signPointsX + x;
        }

        private void AddtoY(string y)
        {
            _signPointsY = _signPointsY + y;
        }

        private void Sign_MouseDown(object sender, MouseEventArgs e)
        {
            _shouldSign = true;
            tmrRefresh.Start();

            AddtoX(e.X.ToString() + ",");
            AddtoY(e.Y.ToString() + ",");
        }

        private void Sign_MouseLeave(object sender, EventArgs e)
        {
            _shouldSign = false;
            tmrRefresh.Stop();

            AddtoX("|");
            AddtoY("|");
        }

        private void Sign_MouseMove(object sender, MouseEventArgs e)
        {
            if (_shouldSign)
            {
                AddtoX(e.X.ToString() + ',');
                AddtoY(e.Y.ToString() + ',');
            }
        }

        private void GenerateSign()
        {
            if (!_bgWorker.IsBusy)
            {
                _bgWorker.RunWorkerAsync();
            }
        }

        public void ClearSignature()
        {
            _signPointsX = "";
            _signPointsY = "";

            if (null != this.BackgroundImage)
            {
                this.BackgroundImage = null;
            }

            _signatureBitmap = null;

            if (_backgroundImageBitmap != null)
            {
                this.BackgroundImage = _backgroundImageBitmap; 
            }

            this.Refresh();
        }

        private void Sign_MouseUp(object sender, MouseEventArgs e)
        {
            _shouldSign = false;
            tmrRefresh.Stop();
            GenerateSign();

            AddtoX("|");
            AddtoY("|");
        }

        private void tmrRefresh_Tick(object sender, EventArgs e)
        {
           GenerateSign();       
        }

        [Obfuscation(Feature = "virtualization", Exclude = false)]
        private Bitmap GetSignImage()
        {
            string[] arrX = _signPointsX.Split('|');
            string[] arrY = _signPointsY.Split('|');
            int CurrX = 0;
            int CurrY = 0;

            Bitmap bmp = null;

            if (_backgroundImageBitmap != null)
                bmp = (Bitmap)_backgroundImageBitmap.Clone();
            else 
                bmp = new Bitmap(this.Width, this.Height);

            Graphics g = null;

            try
            {
                g = Graphics.FromImage(bmp);
                g.SmoothingMode = SmoothingMode.AntiAlias;

                if (_backgroundImageBitmap == null)
                {
                    if (this.FileFormat != ImageFormat.Png || ((this.BackColor != Color.White)))
                    {
                        g.FillRectangle(new SolidBrush(this.BackColor), 0, 0, bmp.Width, bmp.Height);
                    }
                }

                Pen pn = new Pen(new SolidBrush(this.PenColor),this.PenWidth);

                for (int i = 0; i < arrX.Length; i++)
                {
                    if (arrX[i].Length > 0)
                    {
                        string[] innerPointsX = arrX[i].Split(',');
                        string[] innerPointsY = arrY[i].Split(',');

                        PointF[] tfArray = new PointF[innerPointsX.Length - 1];

                        for (int j = 0; j < innerPointsX.Length - 1; j++)
                        {
                            if (innerPointsX[j].Length > 0)
                            {
                                CurrX = Convert.ToInt32(innerPointsX[j]);
                                CurrY = Convert.ToInt32(innerPointsY[j]);

                                PointF tf = new PointF(CurrX, CurrY);
                                tfArray[j] = tf;

                            }
                        }

                        GraphicsPath path = new GraphicsPath();
                        path.AddLines(tfArray);
                        g.DrawPath(pn, path);
                    }
                }

            }
            catch (Exception ex)
            {
                string err = ex.Message.ToString();
                this.ClearSignature();
            }
            finally
            {
                if (null != g)
                    g.Dispose();
            }

            _signatureBitmap = bmp;
            return bmp;
        }

      
    }
}